In the textile industry in recent years there has been a considerable increase in the texturing of yarns. Yarn texturing is one of the processes by which yarn strands may be formed into a
Textured yarns may be formed according to several known processes, some of which include the false-twist method, the knife-edge method, the stuffer box method and the knitdeknit technique. Of these techniques the false-twist method is most widely used and according to this technique friction twist assemblies are provided, each having a plurality of spindles carrying meshed friction discs thereon. Yarns are twisted, heat-set and untwisted in one operation by passing the yarn or thread along a zig-zag path between the spindles and over the edges of the friction disc attached thereto.
A typical spindle assembly includes three or more shafts, each of which has a plurality of circular friction discs or wheels extending radially outwardly from the spindles at spaced points therealong. The friction discs of the spindles, in operation, are intermeshed so that the yarn passes therebetween. An example of such apparatus is illustrated and described in the Schuster U.S. Pat. No. 3,901,011. Note also that it is conventional for each shaft of the spindle to have stacked thereon a plurality of friction discs. Each of such discs includes a flat wheel or base nember with the periphery having bonded thereto a resilient material having relatively high coefficient of friction such as polyurethane, and a hub extending axially upwardly from the central portion of the base member. The hub includes an opening therethrough by means of which one or more of the discs may be attached to the shaft.
Such discs are subjected to wear as the yarn passes over the surface of the polyurethane edge, and therefore the entire disc must be replaced on the average of about once every six months.
This is a relatively expensive operation in that each of the discs as illustrated in FIG. 1 of the Schuster patent is relatively expensive (currently costing approximately $1.75). Additionally, the spindle must be taken out of operation, broken apart, and the worn disc removed, which is also time consuming.